Waterflow retard alarm



C. JG-INSGN ET WTERFT yOW RE 5 .f Hmvwm www; mg@ f C y. acm ZZZ CHR C. C. JOHNSQN AL WATERFLOW RETARD ALARM Filed Feb. 24, 1932 2 Sheets-8heet 2 Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE WATERFLOW RETARD ALARM Application February 24, 1932, Serial No. 594,798

22 Claims.

'Ihis invention relates to retarded alarms for Water-flow-operated sprinkler-systems, and more particularly to retarding means for electric alarm systems to prevent alarm from waterhammer in the sprinkler system though it is noted that in some of the claims the invention is not limited to sprinkler means nor to electric means, nor in some respects even to retarding means.

Objects of the invention are to improve generally the simplicity and eiliciency of such apparatus and to provide a device or apparatus of this kind which is economical, durable, sensitive and very reliable in operation, and economical to manufacture.

Another object of the invention is to provide a completely supervised retarded system of this kind for one or a large number of flow detectors which automatically places itself in alarm-sending condition after a line-break, to be in full alarm-sending condition both before and after both occurrence and repair of the break.

Another object of the invention is to provide a very quick acting alarm, which at the same time will not be actuated by water hammer.

Still other objects of the invention will appear as the description proceeds; and while herein details of the invention are described and claimed, the invention is not limited to these, since many and various changes may be made without departing from the scope of the invention as claimed in the broader claims.

The inventive features for the accomplishment of these and other objects are shown herein in connection with an improved retarded alarm system which, briefly stated, includes service or house lines between and connecting an alarm means and a current source in series circuit, thus to supervise the circuit and hold the alarm means ,against operation, the alarm operating on open circuit, Water-ow-operated normally open detector switches connect said lines, and when closed, short-circuit and operate the alarm means. The alarm means also operates on a break in the house lines, which operation causes normally open shunting switches to close and shunt said lines respectively, to adapt the line for operation of the alarm means, after the break, thereby to set in operation an additional i'lre alarm mechanism.

To prevent operation by water hammer, a water-hammer-operated cut-out switch simultaneously shunts and cuts out the detector switch elements of one line, thus disabling the detector switch. This cut-out switch is controlled by an actuating means including a surge pipe,

communicating with the sprinkler-system supply conduit, and provided with an air chamber and an intermediate constriction, and closed bellows respectively communicating with said pipe on both sides of the constriction, and adapted to operate a pair of electrically conductive levers.

One lever has opposed contacts, the other lever having a contact portion disposed between said opposed contacts, whereby unequal operation of the bellows causes contact and completes an electric circuit to energize an electro-magnet for operating the cut-out switch, thus preventing operation of the alarm means.

In the accompanying drawings showing, by way of example, one of many possible embodiments of the invention,

Fig. l is a diagrammatic showing of the conduits, waterhammeroperated actuating means and the electric alarm system; and

Fig. 2 is a less-detailed diagram of the electric circuit of the alarm system and cut-out switch.

The system as a whole This invention is shown in combination with a sprinkler system main conduit 5, feeding any number of branch conduits 6 feeding sprinkler heads (not shown) which discharge in time of re and cause flow in the conduits, causing the one or more of the fan shaped flow detectors to deflect and close switches 8, 9 and 8', 9 respectively.

In case of fire, these switches short-circuit a supervised alarm circuit, causing a fire alarm. In case or water hammer, these switches are cutout and thereby disabled by water-hammer operated cut-out means forming a part of this invention.

The supervised circuit The circuit is clearly shown by Fig. 2; Fig. 1 shows more detail, both gures being diagrammatic.

A trouble alarm I is set off by a retarded relay I I, both being similar in operation to that shown by the Hopkins Patent No. 1,398,594 issued Nov. 29, 1921, except that the present electro-magnet i2 relay is normally energized and operates when deenergized to let fall the retarded weight I3, in time to release the alarm I0. Therefore, the

present relay is up-side down as compared with f the patent.

The relay is held inoperative and energized by current from a source I5, the supervising circuit being traced through conductors I1, normally closed cut-out switch I8, I 9, house line conductor 25, switch element 9', house line conductor 2l, element 9, house line conductor 22, cut-out switch 23, 2d, conductor 28, to normally closed switch 29, 35, conductor 3l, electromagnet I2, house line conductor 32, switch element 8', house line conductor 33, element 8, house line Vconductor 34 normally closed switch 35, 35, conductor 3l, source I5. Thus the electromagnet is held energized, the

weight i3 held raised and the trouble alarmA IG held against operation.

With the parts in this condition andwithout Water hammer, flow in one or more conduits 6 causes closure of one or more detector switches 8, 9 or 2', 5', thus sho-rt circuiting the solenoid I2, causing alarm as will be explained.

The switch A is the water hammer operated cut out switch, as will be explained, and were this switch not used, the above circuit would be traced directly from conductor Il, to element 9', conductor 2l, element 9 to element 2Q. As will rbe explained, this switch A is merely a cut-out for switch elements 5, 9 to prevent them from operating the system as a result of water hammer.

Line break Should there develop a line break as in line conductors 25, 2l, 22, 32, 33, 35, as for instance breaks at :c or y, the above supervising circuit would be broken, and the magnet I2 deenergized, allowing the weight I3 to slowly descend, in time causing the lifting of the release lever ii, allowing the alarm ID (Fig. 1) to unwind to send a trouble signal and to unwind until the cam projection on the winding arbor l engages the insulated bump l2 carried on switch member 35, of the diagranimatically shown multiple switch B consisting of elements or members 35, 35, 22, 35, 25, 25, wherein the members 35, 29 are shown connected by an insulating bar 55. It is understood that this showing is strictly diagrammatic for purposes of clearness.

The tension and set of the elements of switch B is such that at the midposition of members 35, 2Q all of the switches are closed, and the projection l5 revolves until this condition is effected, this elects shunts around the lines and the breaks a: and y, again closing the circuit, so that the circuit may be traced as follows: source I5, conducto-rs Il, shunt conductor 4l, switch elements 55, 29, 30, conductor 3l, electromagnet I2, conductor 52, shunt conductor 48, switch elements d, 35, 55, conductor 3l, source I5. f

Thus the circuit is complete, electromagnet I2 is energized, and the retard relay is drawn to silencing position. This would immediately silence the alarm lll, except that these alarms, as shown in said patent, run until the required trouble signal is completed and then stop unless the lever 4D is again raised or remains raised.

Fire alarm with broken line yIn this new condition, the system is still in condition to send a re signal by means of water flow eecting the closure of one or more detector switches 8, 9 or 8 9'. Should one of these switches thus close, the electromagnet I2 will be short circuited, again releasing the alarm I.

If the break is at y and switch 8, 9 is closed, the circuit may be traced as follows: source i5, conductors il, 5l, elements 45, 29, conductor 23, elements 2A, 23, conductor 22, elements 9, 8, conductor 34, elements 35, 36, conductor 37, source If the break is at y and switch 8', 9 is closed,

conductor Il, elements i8, I9, conductor 25, elements 5', 8', conductors 32, 48, elements lid, 35, 35, conductor 3l, source I5.

Other circuits with the break at :c will be understood from the foregoing.

Sending the fire alarm If as just stated, a re should cause water ow, and one of these circuits should be formed, shortcircuiting and deenergizing electromagnet I2, the alarm Il! would further unwind, causing the projection 45 to further operate the switch B, maintaining Athe switches 35, 44 and 29, d5 still closed, but opening switches 3S, 35 and 35, 29, and cutting out the electromagnet I2.

At this time there would be no trouble signal, since the untoothed portion 59 of the signal wheel would be opposite the pen 55, but the opening of the switch 35, 35 breaks the circuit through conductor 31 n causing current to flow through conductors 52, 53 and the normally deenergized electromagnet 56 of the fire alarm 55 raising the armature 55, releasing the alarm mechanism and sending the re alarm. In this condition, the circuit may be traced as follows: source I5, conductor I'I, and thence as above explained through a switch 8, 9 or 8' 9' and to conductor 3, thence through conductor 52, electromagnet 56, conductors 53, 3l, source I5.

After a repair is made the serviceman restores the parts to the position shown in the drawings, after which the operation is the same as if the line had never been broken.

Fire alarm with unbroken Zine VIf the line be unbroken, the sending of the re alarm will be easily understood from the foregoing. With unbroken line the parts are as in the drawings and the closure of one or more detector switches, short circuits and deenergizes the electromagnet I2 as above explained, sending in a trouble alarm, closing switches 29, G5, and 35, 4d. However, as the detector switches will lremain closed on account of the continued ilo-w to the sprinkler heads, the electromagnet I2 will continue to be short circuited and deenergized, thus causing the continued revolution of the projection and the opening of the switch 2S, 39 and switch 35, 35 as above explained, thus sending current through the electromagnet 56 and operating the re alarm.

The water hammer operated cut out The above description has assumed absence .of water hammer in the conduits. It is desirable y to have the retardV relay II set to act fairly quickly, so as not to greatly delay the sending of the alarm; and without the cut-out means, whatever hammer is in the conduits 5 operating one or more of the detectors and closing one or more detector switches, might be sufficient to cause the sending of an alarm. Accordingly means are provided to cut-out and thereby disable the detector switches during water hammer.

This means comprises a surge pipe 65 communicating with the main conduit 5 and provided with a yieldable outer end closing means such as the air chamber 6I at one end and an intermediate constriction 62. Closed metallic bellows 63, 64 communicating with said pipe on both sides of the constriction 62 are adapted to be expanded by pressure in the pipe and raise a pair of electrically conducting levers 65, 66

the circuit may be traced as followsz-source I5, each having an end fulcrum 61 and intermediately connected as by a bar 68 to the active portion 69 of the bellows respectively. One lever for instance the lever 95 has a forked active end having inwardly adjustable opposed contacts "I3, 'M adapted at times to be engaged by oppositely pointed contacts 15, 'Il on the active end of the lever 65 and disposed between said adjustable contacts adjacent to, and. just out of contact therewith, respectively.

Conductors i1, 78, 79 electrically connect said levers respectively in series with said source I5 and a solenoid 39 which operates the cut out switch A. Sudden pressure in said pipe 6i] causes the bellows nearer the conduit to move the associated lever 55 more rapidly than the other, thereby making Contact between adjacent contacts '14, l? thereby to energize the solenoid and actuate the switch A.

The constriction 62 allows the pressure in the bellows and air chamber to remain normally equal, except when disturbed by water hammer, as above indicated, the constriction being so small that water-hammer pressure will not have time to be communicated to any considerable extent to the bellows S13.

The cut out switch As already indicated, the switch A includes a pair of normally closed cut yout switches I8, I9, and 23, 24 interposed respectively at both ends of the house line 29, 2l, 22.

The switch A also includes a normally open shunt switch I3, 33 adapted when closed to shunt the current through the conductor 8d around that portion 2e, 2 I, 22 of the house line which includes said cut out switches and the detector switch elements 9, 9', thereby disabling the detector switch.

When the water hammer operates to energize the electromagnet 30, the solenoid 85 is attracted, thus rocking the bell-crank lever 85, SG, raising the insulating block Si on the end of the lever arm 85, thus raising the end of switch element 33, thus closing the shunt switch 83, I 8 and raising switch elements i8 and 24, connected by the insulating bar 89, thereby opening the cut out switches I3, I9 and 23, 2li, thereby to out out and isolate the associated detector switch elements 9, 9 thereby to disable the detector switch, and to simultaneously shunt around such elements through the conductor Se.

With the switch elements 9, 9 thus entirely cut out, any closure of the switches 8, 9 and S', Q' is ineffective, as no current can reach elements 9, 9. Thus the solenoid I2 cannot be short circuited by closure of the switches 8, 9 or 8', 9', and water-hammer cannot be eiective to send an alarm. Should a sprinkler head go off during water-hammer, the sending of the alarm would be delayed only for the short instant of the duration of the water-hammer.

If, during absence of water hammer, a number of sprinkler heads open, or if the number which opens is sufficient, the pressure in bellows S3 will drop enough to cause the closing of contacts '13, '16, thus momentarily maintaining the supervised circuit open. As the water continues to flow, the pressure in bellows G4 must finally become equal to the pressure in bellows 53, whereupon the arm 66 will take a midway position with respect to the arm 65, and contacts "I3, 'I6 will be disengaged, resulting in the functioning of the magnet I2 and finally of the magnet 54 to send a fire alarm.

It has been found from years of eld experience in thousands of sprinkler installations that no definite period of retarding can be established for all installations. Under some service conditions no retarding at all is required; while under other conditions a retarding time of several minutes would not prevent false alarms. A retard period of E to l0 seconds has been arbitrarily established; but where the surge conditions are severe additional means of delaying thD operation of the alarm device are necessary. Thus if only the retard means I0, II were used where water hammer might last more than ten seconds, the water hammer cut-out means is required. It is not desirable to lengthen the period of the retard means II to more than ten seconds, as it is not desirable to delay the alarm more than necessary.

It is not desirable to omit the retard means I0, II, as it performs many functions: It prevents the operation of the alarm 55 from the bouncing of the vanes 'I due to building vibration, foreign bodies floating upward through the riser 6 or pounding on the pipe, any one of which conditions might, and in some cases does, cause the momentary closing of the switches 8, 9.

Also, the trouble alarm I0 causes the mechann ical switching of the line circuits so that an alarm can be sent where either or both of the supervised circuit lines are broken.

Another function of contact 13 is to render the system inoperative on backward ow due to a prolonged surge, which would ultimately cause equalization of pressure in the bellows 6I, 63, following a reduction in pressure due to a leaking city check Valve, a very common source of trouble, which would cause the vane 'I to bounce. pressure in the chamber 6I would be higher (due to the surge) than that in the bellows 63 during the out flow, thus causing contacts 13, 'I6 to engage. The vanes 1 would be moved downwardly and if the ilow stopped suddenly, as it frequently both sides respectively of the constriction; a pair ,-f

of electrically conducting levers mechanically connected to the active portions of the bellows respectively and adapted to contact each other when either one of the bellows expands more than the other; and an electro-magnetic means actuated by such contact to disable the alarm.

2. In combination, a conduit; a surge pipe communicating with the conduit and provided with closing means at the outer end and an intermediate constriction; a pair of closed bellows respectively communicating with said pipe on opposite sides respectively of the constriction; a pair of electrically conducting levers mechanically connected to the active portions of the bellows respectively; one lever having opposed contacts,

the other lever having contacts disposed between said opposed contacts; and an electric circuit in which said levers are connected in series.

1n combination, a surge pipe provided with closing means at the outer end and an interme- ',.1

diate constriction; a pair of closed bellows respectively communicating with said pipe on opposite sides respectively of the constriction; a pair of electrically conducting levers mechanically connected to active portions of the bellows respeci The tively; one lever having opposed contacts, the

other lever having a contact part disposed between said contacts; an electric circuit in which said levers are connected in series; and translating means operated by said circuit.

4. In combination, an alarm means; a source of current; lines between said source and means and connecting said alarm means and source in series circuit to hold the alarm means against operation; a normally open detector switch connected and adapted to close to connect said lines, to short-circuit and operate the alarm means; normally open shunting switches closed by operation of said alarm means, and connected for shunting said lines respectively, an alarm set in operation by the further operation of the alarm means.

5. In combination, a retarded alarm means; a source of current; lines between said alarm means and source and connecting them in series circuit to hold the alarm means against operation; a conduit; a iiow detector therein, a normally open detector switch adapted to be closed by said detector to connect said lines, to shortcircuit and operate the alarl means; normally open shunting switches closed by operation of said alarm means, and connected for shunting said lines respectively, a normally closed switch in one line between said source and detector switch; a rire alarm shunted around and short-circuited by said last named switch and adapted to operate when the switch is opened; means whereby further operation oi the alarm means opens said normally closed switch operating the nre alarm; and cut-out means operated by water-hammer in said con-duit to simultaneously shunt and cut out the detector switch element of one line, the shunting taking place soon enough to prevent operation of the alarm means by the cutting out of theV switch element.

6. n combination, a retarded alarm means; a source of current; lines connected between said alarm means and source connecting them in series circuit to hold the alarm means against operation; a normally open now-controlled detector switch adapted to close to connect said lines to short-circuit and operate the alarm means; normally open shunting switches closed by operation of said alarm means, and connecte-d for shunting said lines respectively, a normally closed switch in one line between said source and detector switch; a ilre alarm shunted around and shortcircuited by said last named switch and adapted to operate whenthe switch is opened; means whereby further operation of the alarm means opens sai-d normally closed switch operating the re alarm; a pair of normally closed cut-out switches interposed in one line respectively on both sides of the detector switch; a normally open shunt switch shunted around the cut out switches; and means for simultaneously closing the switch and opening the cut-out switches.

7. In combination, a retarded alarm means inoperative on closed circuit and operating when open-circuited or short-circuited; a source of current; lines between said alarm means and source and connecting them in series circuit to normally hold the alarm means against operation; one or more normally open flow-detector-controlled detector-switches adapted when closed to connect said lines to short-circuit and operate the alarm means; normally open shunting switches closed by operation of said alarm means, as in case of line break, for shunting said lines respectively around the break, thereby to silence the alarm means and leave the circuit in condition to short circuit and operate the alarm means on closure of the detector switch; a normally closed switch in one line between said source and detector switch; a re alarm shunted around and short-circuited by said last named switch and adapted to operate when the switch is opened; a normally closed switch in the other line between the detector switch alarm means; and means whereby further operation of the alarm means opens said normally closed switches operating the re alarm and breaking the circuit through the alarm means.

8. In combination, water now detectors; a closed circuit controlled thereby; a signal means controlled by the circuit and set in operation by the breaking of said circuit or by said circuit on actuation of said detectors and set in further operation by actuation of the detectors after the break; a iire alarm set in operation only by said further operation; and water hammer operated means for disabling the detectors during water hammer before and after said operations, thereby to prevent confusing water hammer operation with water ilow operation, and to prevent fire alarm from water hammer.

9. In combination, water flow detectors; a circuit controlled thereby; a signal means controlled by the circuit and set in operation by said circuit on circuit defect or actuation of said detectors and set in further operation by further actuation of the detectors; a rire alarm set in operation by said further operation; and water hammer operated means for disabling the detectors during water hammer before and after said operations, thereby to prevent confusing water hammer operation with water flow operation, and to prevent iire alarm from water hammer.

l0. An apparatus comprising a translating means; a source of current; lines between and connecting said means and source in series circuit to hold the translating means against operation; a normally open switch having its elements connected to said lines respectively and adapted to close to connect said lines to shortcircuit and operate the translating means; and normally open shunting switches closed by operation of said translating means, and connected for shunting said lines respectively.

ll. Apparatus as in claim 10 comprising a translating device set in operation by the further operation of the translating means.

l2. n combination, a sprinkler system having flow pipes; water flow detectors having flow vanes in said pipes; a closed supervised circuit controlled by said detectors; a signal means controlled by the circuit and set in operation by the breaking of said circuit, or by said circuit on actuation of said detectors and set in further operation by actuation of the detectors after the break; a rire alarm set in operation only by said further operation; and back flow operated means set in operation by prolonged back surge, before or after said operations, for disabling the detectors during said back surge to prevent operation by the bouncing of the vane caused by sudden stoppage of said back surge, thereby to prevent confusing said bouncing of the vane with waterfiow operation, and to prevent re alarm before or after said break by said bouncing of the vane.

i3. In combination, sprinkler system 'ow pipes; waterflow detectors having flow vaines in said pipes; a closed supervised circuit controlled by said detectors; a signal means controlled by the circuit and set in operation by the breaking of said circuit, or by said circuit on actuation of said detectors and set in further operation by actuation of the detectors after the break; a re alarm set in operation only by said further operation; and water hammer and back surge operated means for disabling the detectors during back surge and water before and after said operations, thereby to prevent operation by water hammer or by bouncing of the varies from sudden stoppage of said back surge, thereby to prevent confusing vane bouncing and water hammer operation with water ow operation, and to prevent re alarm from water hammer or Vane bouncing, before or after said break.

14. In combination, sprinkler system flow pipes; waterflow detectors having i'low vanes in said pipes; a closed supervised circuit controlled by said detectors; a signal means controlled by the circuit and set in operation by the breaking of said circuit, or by said circuit on actuation of said detectors and set in further operation by further actuation of the detectors after the break; a fire alarm set in operation only by said further operation; and water hammer and back surge operated means for disabling the detectors during back surge and water hammer before and after said operations, said means comprising a switch comprising a single pair of switch elements closable to operate said disabling means; means whereby said switch is automatically closed during back surge and during water hammer, thereby to prevent operation by water hammer and by bouncing of the vanes from sudden stoppage of said back surge, thereby to prevent confusing vane bouncing and water hammer operation with water flow operation, and to prevent fire alarm from water hammer or vane bouncing, before or after said break.

15. In combination, a sprinkler system having flow pipes; water flow detectors having flow vanes in said pipes; a closed supervised circuit controlled by said detectors; a signal means controlled by the circuit and set in operation by said circuit on actuation of said detectors; and back flow operated means set in operation by prolonged back surge, before or after said operations, for disabling the detectors during said back surge to prevent operation of the signal by the bouncing of the vane caused by sudden stoppage of said back surge, thereby to prevent confusing said bouncing with waterflow operation.

16. In combination, a normally energized alarm means adapted to operate when deenergized; a source of current; lines connecting said alarm means and source in series circuit to hold the alarm means against operation; a break in the line deenergizing and operating the alarm means; said alarm means being between the lines; normally open detector switches spaced along intermediate portions of the respective lines and adapted to be closed to connect said lines to each other to short-circuit and operate the alarm means; and normally open shunting switches adapted to be closed by operation of said alarm means when deenergized, and connected and adapted when closed to shunt around said intermediate portions respectively, thereby to restore said series circuit and energize and stop the alarm means, if the alarm means were operated by line break and the detector switches are open; said shunting switches when closed connecting both ends of said intermediate portions to the respective lines, whereby detectorswitch closure after such line break in one of said intermediate portions, may again short circuit and operate the alarm means.

17. In combination, a normally energized alarm means adapted to operate when deenergized; a source of current; lines connecting said alarm means and source in series circuit to hold the alarm means ragainst operation; a break in the line deenergizing and operating the alarm means; said alarm means being between the lines; normally open detector switches spaced along intermediate portions of the respective lines and adapted to be closed to connect said lines te each other to short-circuit and operate the alarm means; normally open shunting switches adapted tc be closed by operation of said alarm means, and connected and adapted when closed to sh 1+ around said intermediate po '.'icns respectiv thereby to restore said series circuit and energize and stop the alarm means, if the alarm means were operated by line break and the detector switches are open; said shunting switches when closed connecting both ends of said intermediate portions to the respective lines, whereby detector-switch closure after line break in said intermediate portion and consequent shunting may again short circuit and operate the alarm means; an alarm set in operation by the further operation of the alarm means; and means to simultaneously cut out and shunt one of said intermediate portions and the detector switch elements therein.

18. In combination, a conduit subject to slow pressure change and water hammer; an alarm means operated by ow in the conduit to operate the alarm; a surge pipe communicating with the conduit and provided with a substantially closed outer end and an intermediate constriction; a pair of closed bellows, one communicating with said pipe on one side of the constriction and the other bellows communicating with the pipe on the other side of the constriction; a pair of electrically conducting levers mechanically connected to the active portions of the bellows respectively and adapted to contact each other when either one of the bellows expands more than the other; and electric means actuated by such contact to disable the alarm; said constriction allowing equilibrium to be established between said bellows when the pressure in the conduit slowly changes, thereby to prevent the disabling of the alarm by said slow rise or fall in said pressure.

19. The combination of a surge pipe provided with an intermediate constriction and with an inner pressure opposing means at the outer end of the pipe; pressure-operated means respectively communicating with said pipe on opposite sides of the constriction and adapted to be unevenly operated by liquid in the pipe when the liquid surges toward or from said outer end; and a translating means actuated by uneven operation of the pressure means when one pressure operated means is operated more than the other, whereby said combination produces the new and better result that the translating means is operated by said surge when moving either toward or from said outer end.

20. In combination, an alarm means held against operation by current passing therethrough and released for operation when said current is suliciently reduced; a source of current; lines between said source and means and connecting said lines, alarm means and source in series circuit to hold the alarm means against operation; a normally open detector switch having its elements connected to said lines respectively and adapted. to close to connect said lines, to short-circuit and operate the alarm means; normally open shunting switches connected for shunting said lines respectively, and said elements connected thereto, when the shunting switches are closed, and adapted to be closed by operation of said alarm means when said operation is caused by a break in either of said lines, closure of the shunting switch around the break reestablishing the circuit and arresting the alarm means, leaving the alarm means in condition for further operation by the closure of the detector switch; additional alarm means; and means set in operation by the further operation of the iirst named alarm means operating the additional means.

2l. In combination, a translating means held against operation by current passing therethrough and released for operation when said current is suinciently reduced; a source of current;- lines between said source and means and connecting said lines, alarm means and source in series circuit to hold the alarm means against operation, said translating means operating when not so held; a normally open detector switch having its elements connected to said lines respectively and adapted to close to connect said lines, to short-circuit, and operate, the translating means; normally open shunting switches connected for shunting said lines respectively, and said elements connected thereto, when the shunting switches are closed, and adapted t0 be closed by operation of said alarm means, whereby when said operation is caused by a break in either of said lines,l the closure of the shunting switch shunts around the break and reestablishes the circuit and-arrests the translating means, leaving the translating means in condition for further operation by the closure of the detector switch.

22. In combination, a flow detector operable by ow and water hammer; an alarm means held against operation by current passing therethrough and released for operation when said current is sufficiently reduced; a source of current; lines between said source and means and connecting said alarm means and source in series circuit to hold the alarm means against operation; a normally open detector switch operated by said detector and having its elements connected to said lines respectively and adapted to close to connect said lines, to short-circuit and operate the alarm means; normally open shunting switches connected for shunting said lines respectively, and the elements connected thereto, when the shunting switches are closed, and adapted to be closed by operation of said alarm means when said operation is caused by a break in either of said lines, closure of the shunting switch around the break and reestablishing the circuit and arresting the alarm means, leaving the alarm means ready for further operation by the closure of the detector switch; additional alarm means set in operation by the further operation of the first named alarm means; and means operated by said water hammer to first shunt and then cut out the detector switch element of one line, thereby preventing the operation of said additional means from water hammer after said first named alarm means has been operated by line break.

CLARENCE C. JOHNSON.

RICHARD M. HOPKINS.

RICHARD F. SPAMER. 

